This document gives implementation and operational considerations for using TLS-PSK with RADIUS.
RFC6614 and RFC7360 define TLS and DTLS transports for RADIUS. However, neither of those documents discuss how to use TLS-PSK.
While FreeRADIUS has implemented TLS-PSK for nearly a decade, its use is not wide-spread.
This document is for the IETF RADEXT WG http://datatracker.ietf.org/wg/radext